Methods and apparatuses for removing meat from the bone of an animal part such as a poultry thigh have been proposed in, for example, prior patent publications U.S. Pat. No. 3,672,000; U.S. Pat. No. 4,327,463; U.S. Pat. No. 4,495,675; U.S. Pat. No. 4,639,974; and U.S. Pat. No. 4,893,378. In such methods and apparatuses a sleeve of meat surrounding the bone shaft is progressively stripped from the bone and forced over the second knuckle to free the meet from the bone. To permit passage of the meat over the second knuckle, meat stripper assemblies or diaphragms employed by the prior art need to have an opening large enough to allow passage of the second knuckle through the stripper. A meat stripper having an opening of a fixed size that is large enough to pass the second knuckle will not work properly as significant portions of meat will be left on the bone shaft, while the meat that has been removed will be damaged and become undesirable for further use. It is for at least this reason that in most known deboning assemblies, the opening of the meat stripper assembly is made to be variable.
Several mechanisms have been conceived to allow the stripper assembly opening to be varied in size when engaging and passing the bone and second knuckle of an animal part. Some of these mechanisms have added substantial complication to, as well as hampered the reliability of, the known meat removing and deboning apparatuses. Therefore a more recent approach has been to employ flexible rubber or elastomeric stripper disks having a center aperture providing a circumferential stripper edge. As a bone is forced through such a stripper disc, the aperture varies in size to accommodate size changes in the bone and widens to allow passage of the knuckles.
While the use of flexible stripper disks has reduced structural complications and enhanced reliability of operation, it has also introduced problems associated with the relatively rapid wear of the flexible stripper disks and the accompanying downtime for periodic replacements worn stripper disks. It is not uncommon, for instance, for these flexible stripper disks to require replacement after processing 600 kg of meat. Furthermore it has been necessary to insert the animal part initially at one of its knuckle ends through the central aperture of the flexible stripper disk. The management of the animal part to insure reliable initial insertion through the disc is not an easy matter to control, particularly given the ever increasing demand for meat processing speed. Thus, misfeeds of animal parts occur, resulting in damaged product and lower production rates.
Accordingly, a need exists in the poultry processing industry to overcome or ameliorate at least one of the disadvantages of the prior art addressed above as well as other disadvantages. There is a related need for alternative structures that are less cumbersome in assembly and operation and that moreover can be made relatively inexpensively. A need at least exists to provide consumers with a useful choice. It is to the provision of a method and apparatus that addresses these and other needs that the present invention is primarily directed.